The present invention relates generally to a compressor and more specifically to a mechanism in the compressor for separating oil from refrigerant gas and then returning the separated oil to a crank chamber or a suction chamber of the compressor.
Japanese Unexamined Patent Application Publication No. 9-209928 discloses a compressor in which a muffler chamber is formed in the top of a cylinder block in communication with a discharge chamber for separating oil from discharged gas. A communication hole is formed in the bottom of the muffler chamber for communication with a bolt hole in the upper part of the cylinder block. The upper bolt hole communicates with a bolt hole in the lower part of the cylinder block through a narrow throttled passage formed in a gasket. The throttle passage serves as an oil circulating passage. The lower bolt hole communicates with a crank chamber.
The oil separated in the muffler chamber is temporarily reserved in the upper bolt hole. The oil then flows through the throttle passage and the lower bolt hole and into the crank chamber.
The narrow throttled passage for communication between the upper bolt hole and the lower bolt hole requires an additional special machining to form a fine groove through a gasket.
An object of the present invention is to provide a compressor in which an oil return passage is formed without requiring any additional machining.